Normal systolic blood pressure at age 38 should be <140 mmHg and diastolic blood pressure should be <90 mmHg. Although blood pressure may vary slightly according to gender and age, it should still fluctuate within the normal blood pressure range, so the blood pressure reference value for 38 years old is consistent with the normal blood pressure value for normal adults. The normal blood pressure range for a 38-year-old is a systolic blood pressure <140 mmHg and a diastolic blood pressure <90 mmHg, which can be further categorized into two types of blood pressure: normal blood pressure and normal-high blood pressure. Normal blood pressure is defined as a systolic blood pressure of <120 mmHg and a diastolic blood pressure of <80 mmHg, while normal high blood pressure is defined as a systolic blood pressure of 120-139 mmHg and/or a diastolic blood pressure of 80-89 mmHg, the latter of which is also considered normal but carries an increased risk of developing hypertension. Regular blood pressure testing is recommended regardless of age, with timely retesting and medical attention for any abnormalities.